Optical illusions occur when what the eyes see conflicts with what the brain expects.
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The human eye blinks an average of 4,200,000 times a year.
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Tigers can see 6 times better at night than humans.
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There are glasses which allow a red-green color-blind person to see colors the way everyone else does.
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Sheep, goats, octopuses, and toads have rectangular pupils.
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Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
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Those things you see in your eyes when you stare into space are called Mouches Voltanes, which are also broadly referenced to as Floaters.
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When you are looking at someone you love, your pupils dilate, they do the same when you are looking at someone you hate.
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